This invention relates to the conversion of chemical energy to electrical energy, and more particularly to a new and improved enclosure for lithium-iodine cells and a method of making the same.
One area of use of the present invention is in providing electrical power to inaccessible devices in the human environment, for example to an implanted cardiac pacemaker, although the principles of the present invention can be variously applied. Various batteries for implantable cardiac pacemakers have been proposed, but heretofore all have certain limitations. Lithium-iodine cells are available which advantageously have an open circuit voltage about twice that of the mercury cell, do not generate gas during operation, and have a non-corrosive electrolyte. A problem can arise, however, from the viscous nature of the iodine-containing material such as an iodine complex in that it tends to flow and may possibly form a short circuit path between the anode and cathode. It is important to prevent such leakage, not only to maintain cell operation but also to prevent harm to a human body in which the cell may be implanted.